Circuit board with a substrate made of silicon

ABSTRACT

A circuit board with a substrate made of silicon includes a silicon substrate made of silicon; an adhering layer which is a gluing layer and is adhered on the silicon substrate; a metal layer formed as a metal plate layer or a metal circuit layer; the metal layer being adhered on the adhering layer; and wherein the metal layer is formed with metal circuits by screen printing. Electronic elements are adhered on the metal layer to form as circuits with specific functions. Materials of the adhering layer contains Organic silicon polyester copolymer resin, Ethyl acetate and Organic silicon resin. Material of the metal layer is selected from copper, aluminum, sliver, and gold. A packaging silicon layer encapsulates the metal layer and the electronic elements for packaging. Material of the metal layer is selected from copper, aluminum, sliver, and gold.

The present invention is a divisional application of U.S. patentapplication Ser. No. 15/841,320, filed at Dec. 14, 2017 which isinvented by and assigned to the applicant of the present invention, andthus the contents of the U.S. patent application Ser. No. 15/841,320 isincorporated into the present invention as a part of the presentinvention.

FIELD OF INVENTION

The present invention relates to circuit board materials, and inparticular to a circuit board with a substrate made of silicon.

BACKGROUND OF THE INVENTION

As shown in FIG. 1, the conventional printed circuit is made of PET orPI boards (films) which is made as a substrate 10′. Then a metal layer30′ is adhered to the substrate 10′ by using an adhesive layer 20′.Material of the metal layer 30′ is selected from copper, silver, gold,etc. If packaging is necessary, silicon 40′ is added to the printedcircuit.

Generally, printed circuits are classified as hard boards and softboards. The hard boards are made of FR4, aluminum, or ceramics. The softboards are made of PET, PI, etc. The structure of soft boards has somedefects in practical usages. The main reasons are that PET or PI are,not usable in high temperatures over 130° C. This high temperature willinduce deformation of the circuit or the electric properties of theelements on the circuit boards are shifted, for example, impedances arechanged so that precise data transfer cannot be achieved.

The extension property of PET or PI is not preferable. In manyapplications, for example, biological chips, these circuit boards arenot suitable due to bad extension property. Furthermore PET or PI boardsare not compactable biologically. The boards are easily reacted withperipheral organs biologically.

Therefore, the present invention desired to provide a novel inventionwhich can improve above mentioned defects.

SUMMARY OF THE INVENTION

Accordingly, to improve above mentioned defects, the present inventionprovides a circuit board with a substrate made of silicon, wherein asilicon substrate is used to replace conventional substrates which usePET or PI. The silicon is more extensible and flexible than the priorart PET substrate. Furthermore silicon substrate is bendable so that itis suitable for forming bendable circuit board. Silicon has lowdielectric coefficient which is suitable as substrates for antennas orother wireless circuits. Furthermore, the temperature tolerance ofsilicon substrate is over 200 degree C. so that the present invention isusable in high temperatures, such as medical usages. Generally, hightemperature sterilization is over 160 degrees, but the conventional PETor PI substrates cannot be used under such temperatures. Moreover, thesilicon substrate 10 is water proof and heat tolerant so that they canbe used in various environments and thus productions of siliconsubstrates are easily. Further, silicon substrates are difficult toreact chemically with other biological organs, and thus they aresuitable in applications of biologics, such as forming as biologicalchips.

To achieve above object, the present invention provides a circuit boardwith a substrate made of silicon, comprising: a silicon substrate madeof silicon; an adhering layer which is a gluing layer and is adhered onthe silicon substrate; a metal layer formed as a metal plate layer or ametal circuit layer; the metal layer being adhered on the adheringlayer; and wherein the metal layer is formed with metal circuits byscreen printing. Electronic elements are adhered on the metal layer toform as circuits with specific functions. Materials of the adheringlayer contains Organic silicon polyester copolymer resin, Ethyl acetateand Organic silicon resin. Material of the metal layer is selected fromcopper, aluminum, sliver, and gold. A packaging silicon layerencapsulates the metal layer and the electronic elements for packaging.Material of the metal layer is selected from copper, aluminum, sliver,and gold.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view of a prior art printed circuit board.

FIG. 2A shows a schematic cross section view of the present invention.

FIG. 2B is a perspective schematic view of the present invention.

FIG. 3 shows the manufacturing process of the present invention.

FIG. 4 is a schematic view showing the etching process of the presentinvention.

FIG. 5 is a flow diagram about the manufacturing method when the presentinvention is applied to screen printing.

FIG. 6 is a schematic view which shows that the present invention isapplied to screen printing.

DETAILED DESCRIPTION OF THE INVENTION

In order that those skilled in the art can further understand thepresent invention, a description will be provided in the following indetails. However, these descriptions and the appended drawings are onlyused to cause those skilled in the art to understand the objects,features, and characteristics of the present invention, but not to beused to confine the scope and spirit of the present invention defined inthe appended claims.

With reference to FIGS. 2A to 4, the structures of the present inventionare shown. The present invention is related to a circuit board with asubstrate made of silicon which includes following elements.

A silicon substrate 10 (With reference to FIGS. 2A and 2B) is made ofsilicon which is more extensible and flexible than PET substrate.Furthermore, silicon is tolerable with temperatures higher than 200° C.

An adhering layer 20 is adhered on the silicon substrate 10. Materialsof the adhering layer 20 contains Organic silicon polyester copolymerresin, Ethyl acetate and Organic silicon resin.

A metal layer 30 is formed as a metal plate layer or a metal circuitlayer. If the metal layer 30 is formed as a metal plate layer, it can beformed as circuits by etching or screen printing. The metal layer 30 isadhered on the adhering layer 20. Material of the metal layer 30 isselected from metals such as copper, aluminum, sliver, gold, etc.Practically, other electronic elements 35 may be arranged on the metallayer 30 (as shown in the schematic view of FIG. 2) so as to form as afunctional circuit.

If in packaging, a packaging silicon layer 40 encapsulates the metallayer 30 (maybe including the electronic elements 35 thereon) forpackaging the metal layer 30 and the electronic elements 35 thereon.

With reference to FIGS. 3 and 4, a manufacturing process for forming anetching circuit board on the silicon substrate is illustrated. Theprocess will be described herein. The process comprises the followingstep of:

Preparing metal layer 30 for forming a circuit; and guiding the metallayer 30 to a coating unit 110; and coating glue material on the metallayer 30 so as to form with a gluing layer 20 (step 802);

Guiding the metal layer 30 with the gluing layer 20 to a first bakingunit 121 for baking (step 804);

Spraying silicon material from a silicon material barrel 100 into aspace between two rollers 1; wherein the rollers will compress and rollthe silicon material to be form as a silicon substrate 10 with apredetermined width (step 806);

By the two rollers 2 and a transferring belt 200, guiding the siliconsubstrate 10 to a metal adhering unit 130, and meanwhile guiding themetal layer 30 with the gluing layer 20 to the metal adhering unit 130;adhering the gluing layer 20 of metal layer 30 to the silicon substrate10 so as to form as a compound board 50 which serves to be formed as acircuit board (step 810);

Guiding the compound board 50 to a second baking unit 122 for baking thecompound board 50 (step 820);

In the present invention, the compound board 50 may be a plate likestructure or be curled for storage or transferring. If necessary, thecurled compound board 50 can be straightened for forming circuits orpackaging in the succeeding process.

Next, transferring the baked compound board 50 to an etching tank 140for etching (step 840); wherein liquid for etching may be alkaline oracidic, for example, copper chloride.

Next, forming circuit on the etched compound board 50 (step 850); thesesteps are known in the arts, and thus the details will not be furtherdescribed herein.

If packaging is necessary, the functional circuit 37 formed byelectronic elements 35 on the metal layer 30 is packaged with apackaging silicon layer 40 by using a packaging device 150 (step 850).

With reference to FIGS. 5 and 6, the process for forming printed circuitboard on the silicon substrate will be described herein.

Spraying silicon material from a silicon material barrel 100 into aspace between two rollers 1; wherein the rollers will compress and rollthe silicon material to be form as a silicon substrate 10 with apredetermined width (step 906);

By the two rollers 2 and a transferring belt 200, guiding the siliconsubstrate 10 to a gluing material coating unit 110, and then gluingmaterial is coated on the silicon substrate 10 so as to form a gluinglayer 20 (step 907);

Guiding the silicon substrate 10 with the gluing layer 20 to a firstbaking unit 121 for baking the silicon substrate 10 with the gluinglayer 20 (step 908)

Then guiding the baked silicon substrate 10 with the gluing layer 20 toa screen printing plate adding unit 160 so as to adhere a screen plate161 on the gluing layer 20 to form with an integrated board 60; whereinthe screen plate 161 has hollowed areas 165 for forming circuits in thesucceeding process (step 909)

Next transferring the integrated board 60 to an ink unit 170 to addmetal ink on the hollowed areas of the screen plate 161; and then takingout the screen plate 161 and the left metal inks 171 are formed as ametal layer 30 which is a printed circuit. In that, the metal layer 30,the silicon substrate 10 and the gluing layer 20 are formed as acompound board 50 (step 910). The metal inks 181 are selected from metalmaterials, such as copper, aluminum, silver, gold, etc.

Guiding the compound board 50 to a second baking unit 122 for baking thecompound board 50 (step 911)

If packaging is necessary, other electronic elements 35 are installed orformed on the metal layer 30 (those shown on the drawings are onlyschematic views) to form as a functional circuit 37; then a packagingmachine 150 forms a packaging layer 40 on the compound board 50 (step912).

In the present invention, a silicon substrate is used to replaceconventional substrates which use PET or PI. The silicon is moreextensible and flexible than the prior art PET substrate. Furthermoresilicon substrate is bendable so that it is suitable for formingbendable circuit board. Silicon has low dielectric coefficient which issuitable as substrates for antennas or other wireless circuits.Furthermore, the temperature tolerance of silicon substrate is over 200degree C. so that the present invention is usable in high temperatures,such as medical usages. Generally, high temperature sterilization isover 160 degrees, but the conventional PET or PI substrates cannot beused under such temperatures. Moreover, the silicon substrate 10 iswater proof and heat tolerant so that they can be used in variousenvironments and thus productions of silicon substrates are easily.Further, silicon substrates are difficult to react chemically with otherbiological organs, and thus they are suitable in applications ofbiologics, such as forming as biological chips.

The present invention is thus described, it will be obvious that thesame may be varied in many ways. Such variations are not to be regardedas a departure from the spirit and scope of the present invention, andall such modifications as would be obvious to one skilled in the art areintended to be included within the scope of the following claims.

What is claimed is:
 1. A circuit board with a substrate made of siliconcomprising: a silicon substrate made of silicon; an adhering layer whichis a gluing layer and is adhered on the silicon substrate; a metal layerformed as a metal plate layer or a metal circuit layer; the metal layerbeing adhered on the adhering layer; and wherein the metal layer isformed with metal circuits by screen printing.
 2. The circuit board witha substrate made of silicon as claimed in claim 1, wherein electronicelements are adhered on the metal layer to form as circuits withspecific functions.
 3. The circuit board with a substrate made ofsilicon as claimed in claim 1, wherein materials of the adhering layercontains Organic silicon polyester copolymer resin, Ethyl acetate andOrganic silicon resin.
 4. The circuit board with a substrate made ofsilicon as claimed in claim 2, wherein material of the metal layer isselected from copper, aluminum, sliver, and gold.
 5. The circuit boardwith a substrate made of silicon as claimed in claim 2, wherein apackaging silicon layer encapsulates the metal layer and the electronicelements for packaging.
 6. The circuit board with a substrate made ofsilicon as claimed in claim 1, wherein material of the metal layer isselected from copper, aluminum, sliver, and gold.
 7. The circuit boardwith a substrate made of silicon as claimed in claim 1, wherein thecircuit board is formed by spraying silicon material from a siliconmaterial barrel into a space between two rollers; wherein the rollerswill compress and roll the silicon material to be form as a siliconsubstrate with a predetermined width; by the two rollers and atransferring belt, guiding the silicon substrate to a gluing materialcoating unit, and then gluing material being coated on the siliconsubstrate so as to form a gluing layer; guiding the silicon substratewith the gluing layer to a first baking unit for baking the siliconsubstrate with the gluing layer; guiding the baked silicon substratewith the gluing layer to a screen printing plate adding unit so as toadhere a screen plate on the gluing layer to form with an integratedboard; wherein the screen plate has hollowed areas for forming circuitsin the succeeding process; transferring the integrated board to an inkunit to add metal ink on the hollowed areas of the screen plate; andthen taking out the screen plate and left metal inks are formed as ametal layer which is a printed circuit; in that, the metal layer, thesilicon substrate and the gluing layer are formed as a compound board;and guiding the compound board to a second baking unit for baking thecompound board.